The present invention relates to an apparatus for sensing weight, and more particularly, to an apparatus for sensing the weight of an occupant of a vehicle seat.
A conventional vehicle occupant weight sensing apparatus includes a weight sensor placed between a vehicle seat frame and a support mount for the seat. The sensor is directly within the vertical load path of the occupant""s weight and responds to the weight of the occupant of the seat. In addition, the sensor may respond to torque loads between the seat and the support mount. Since the seat frame and the support mount must withstand large lateral loads (i.e., during crash conditions), typically the sensor also must withstand large lateral loads.
Accordingly, the sensor is typically constructed to withstand lateral loads. This may lessen the sensitivity of the sensor in the vertical load path. Thus, the sensor may not produce a reliable weight output signal.
A weight sensing apparatus which decouples the lateral and vertical loads would allow the construction of a weight sensor that does not have to withstand lateral loads and thereby may be more likely to produce a more accurate occupant weight output signal.
The present invention relates to an apparatus for use in a vehicle having a seat for a vehicle occupant and a vehicle floor pan for supporting the vehicle seat. The apparatus includes a seat frame for supporting the vehicle seat, a support mount connected to the vehicle floor pan, a lever, and a sensor. The vehicle seat frame supports a weight load of the vehicle occupant in the vehicle seat. The support mount transmits the weight load of the vehicle occupant in the vehicle seat from the vehicle seat frame to the vehicle floor pan. The seat frame moves vertically relative to the support mount as the weight load on the vehicle seat frame changes. The lever has a first end and a second end opposite the first end. The lever is rotatably attached to the vehicle seat frame and rotatably attached to the support mount. The lever has a portion which bends when the weight load of the vehicle occupant is transmitted by the lever from the vehicle seat frame to the support mount. The sensor detects bending of the portion of the lever and provides an output weight signal indicative of the amount of bending of the portion of the lever.